//
//  use_of_fseek.c
//  
//
//  Created by Bibhas Ghoshal on 11/08/20.
//

#include <stdio.h>
#include <stdlib.h>

struct threeNum
{
    int n1, n2, n3;
};

int main()
{
    int n;
    struct threeNum num;
    FILE *fptr;
    
    if ((fptr = fopen("./program.bin","rb")) == NULL){
        printf("Error! opening file");
        
        // Program exits if the file pointer returns NULL.
        exit(1);
    }
    
    // Moves the cursor to the end of the file
    fseek(fptr, -sizeof(struct threeNum), SEEK_END);
    
    for(n = 1; n < 5; ++n)
    {
        fread(&num, sizeof(struct threeNum), 1, fptr);
        printf("n1: %d\tn2: %d\tn3: %d\n", num.n1, num.n2, num.n3);
        fseek(fptr, -2*sizeof(struct threeNum), SEEK_CUR);
    }
    fclose(fptr);
    
    return 0;
}